In the conveyance of paper, or other articles and substrates, often times the handling of stacks is required. When articles are stacked and a single article needs to be moved from the top of the stack, often times static and frictional adhering forces make it difficult to smoothly move the top article from the stack. This is particularly a problem when handling heavy or glossy media.
European Patent Application No. EP 1 975 735 describes use of radial blowers and a duct system forming low pressure suction chambers to aerate the sides of the stack and to adhere the top sheet in the stack to a belt.
U.S. Pat. No. 6,082,728 describes use of an axial fan likewise running through a duct as a low pressure suction chamber on the opposite side of a belt from paper being conveyed thereon to lift the uppermost sheet from a stack. The uppermost sheet is first separated from the stack using an air knife providing compressed air from a duct system to below the uppermost sheet.
U.S. Pat. No. 6,565,321 describes a vortex attractor. An impeller including a plurality of radial blades extending in a direction of the rotation axis is provided to generate a vortex flow. The vortex flow provides a central negative low pressure region which can be used to attract an object.